It's perfectly possible to not have FOUC with traditional template languages like mustache, and I don't think having "turing completeness" in your templates is a good thing. Frameworks like Ember.js have also shown that you don't need to manually write bindings to handle when your models change.
That being said, I do see the advantage gained with the virtual DOM you generate from the templates. I'd be interested to see if it was possible to integrate other templating languages in via plugin.